Surgical-site infection (SSI) contributes to postoperative morbidity and death. More than one third of postoperative deaths are related, in large part, to SSIs. Over the past several decades, minimally invasive surgical approaches (vaginal, laparoscopic, and robotic) have emerged for treatment of abdominal and pelvic cancers. Compared with open surgery, use of minimally invasive surgery (MIS) for many kinds of surgery lowers the rates of SSI and other postoperative complications, allows shorter hospital stays, and therefore decreases the cost of care.
The primary aim of this study was to determine perioperative variables associated with the risk of SSI within 30 days after surgery in endometrial cancer (EC) patients and to identify modifiable variables. Perioperative variables were abstracted from records of patients who underwent surgical staging for EC between 1999 and 2008 at Mayo Clinic in Rochester, Minn. Primary outcome was occurrence of SSI according to the American College of Surgeons National Surgical Quality Improvement Program definitions. Multivariable counseling and global models were constructed for the assessment of perioperative predictors of superficial incisional SSI and organ/space SSI. Thirty-day cost of SSI was estimated.
A total of 1369 patients met the study inclusion criteria. Of these, 136 (9.9%) had an SSI within 30 days of EC staging surgery. With the counseling model, factors independently associated with superficial incisional SSI included obesity, American Society of Anesthesiologists score greater than 2, current smoking, preoperative anemia (hematocrit <36%), and staging through laparotomy. With the global model, independent predictors of superficial incisional SSI were increasing obesity, American Society of Anesthesiologists score greater than 2, current smoking, laparotomy, and intraoperative transfusion. Independent predictive risk factors for organ/space SSI in the counseling model were older age, smoking, elevated preoperative glucose (>110 mg/dL), and a prior history of methicillin-resistant Staphylococcus aureus infection. Independent predictors of organ/space SSI in the global model were older age, current smoking, a history of vascular disease, prior methicillin-resistant S. aureus infection, greater estimated blood loss, and lymphadenectomy or small or large bowel resection. Median increase in cost of SSI within 30 days of EC staging surgery was $5447.
These prediction models may help identify patients with a priori increased SSI risk and may be useful to individualize preoperative patient counseling. Hyperglycemia and smoking are modifiable risk factors. The 30-day costs of SSI are substantial and are decreased by MIS approaches that decrease the rate of SSI. Minimally invasive surgery should be the preferred surgical route.
Divisions of Gynecologic Surgery (J.N.B.-G., S.C.D., A.M., J.R.M., W.A.C., K.C.P.), Health Care Policy and Research (B.J.B., L.H.), and Biomedical Statistics and Informatics (A.L.W., M.E.M.), Mayo Clinic, Rochester, MN